Constant risk aversion in stochastic contests with exponential completion times

This article analyzes a class of stochastic contests among multiple players under risk‐averse exponential utility. In these contests, players compete over the completion of a task by simultaneously deciding on their investment, which determines how fast they complete the task. The completion time of the task for each player is assumed to be an exponentially distributed random variable with rate linear in the player's investment and the completion times of different players are assumed to be stochastically independent. The player that completes the task first earns a prize whereas the remaining players earn nothing. The article establishes a one‐to‐one correspondence between the Nash equilibrium of this contest with respect to risk‐averse exponential utilities and the nonnegative solution of a nonlinear equation. Using the properties of the latter, it proves the existence and the uniqueness of the Nash equilibrium, and provides an efficient method to compute it. It exploits the resulting representation of the equilibrium investments to determine the effects of risk aversion and the differences between the outcome of the Nash equilibrium and that of a centralized version.© 2016 Wiley Periodicals, Inc. Naval Research Logistics 66:4–14, 2019     

Tripwires and free-riders: Do forward-deployed U.S. troops reduce the willingness of host-country citizens to fight for their country?

This article investigates the relationship between U.S. overseas troops and the willingness of the citizens of host states to fight for their country. The study joins the long-running debate about burden-sharing and free-riding among U.S. allies. Unlike most previous empirical studies, we focus on non-material or intangible measures of the underlying concepts. Our dependent variable estimates the proportion of citizens expressing a willingness to fight for their country. Scores at the aggregate-national as well as the individual level are shaped by the presence of U.S. military forces, which act as a “tripwire” signaling credible security commitments. This increases opportunities of (non-material) free-riding. We present both bivariate and multivariate analyses covering the period 1981–2014 to test this supposition. Findings indicate that once U.S. troop levels reach a certain threshold (between 100 and 500 troops), citizens’ willingness to fight drops significantly. This likely reflects non-material free-riding.     

Fencing the bear? Explaining US foreign policy towards Russian interventions

Despite the burgeoning literature on Russia’s renewed power politics, little attention has been paid to the fact that US reactions towards Russia’s military interventions were all but coherent. The USA has chosen weak measures in Georgia in 2008 (shaming) compared to its assertive response in Ukraine in 2014 (sanctions, hard deterrence). This article assesses the explanatory power of neorealist, liberal and constructivist theories for the variation in US reactions towards Russian interventions in Georgia and Ukraine. Our argument is that the constructivist perspective explains the cases best as it highlights the power and communality of normative assessments. The Ukraine crisis was perceived by the USA as a violation of core international norms, especially the non-use of force and the principle of territorial integrity. Relevant international norm carriers shared this assessment of the conflict. In contrast, the perception of the Georgian war centred on the issue of democracy promotion. While democracy is an important aim of US foreign policy, it does not summon the same normative importance as general principles of international law. Furthermore, the perception of the Georgian war remained contested among Western allies, which decreased the communality of the normative assessment.     

“The major prize”: apartheid South Africa’s accession to the Treaty on the Non-Proliferation of Nuclear Weapons, 1988–91

ABSTRACT

This article focuses on the final years of South Africa’s nuclear-weapon program, particularly on the decision-making process leading up to the signature of the 1968 Treaty on the Non-Proliferation of Nuclear Weapons (NPT) by the South African government in 1991. In August 1988, after two decades of defiance, negotiations between the apartheid government and the NPT depository powers (the United Kingdom, the United States, and the Soviet Union) ensued at the International Atomic Energy Agency (IAEA) in Vienna. Despite South Africa being the only state to give up its indigenously developed nuclear weapons and subsequently join the nonproliferation regime, little is known about how the national position on NPT accession and IAEA safeguards evolved. Research carried out in multiple archives using hitherto untapped primary sources and interviews with key actors from several countries show how domestic and regional political dynamics influenced Pretoria’s position on entering the nonproliferation regime. In the process, the F.W. de Klerk government managed to skillfully exploit international proliferation fears to advance its own agenda, thereby connecting South African NPT accession with that of the neighboring Frontline States coalition of Angola, Mozambique, Tanzania, Zambia, and Zimbabwe.     

On a Markov‐modulated shock and wear process

We present transient and asymptotic reliability indices for a single‐unit system that is subject to Markov‐modulated shocks and wear. The transient results are derived from the (transform) solution of an integro‐differential equation describing the joint distribution of the cumulative degradation process and the state of the modulating process. Additionally, we prove the asymptotic normality of a properly centered and time‐scaled version of the cumulative degradation at time t. This asymptotic result leads to a simple normal approximation for a properly centered and space‐scaled version of the systes lifetime distribution. Two numerical examples illustrate the quality of the normal approximation. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009     

The New Global Security Landscape: The Road Ahead

If one could look through the familiar artificial political lines and colors of a current world map into the twenty-first century strategic reality, one could see a complex new security arena. A deeper look into that picture would provide magical snapshots that show several types of ambiguous and asymmetric conflicts, and state failure - and their causes and consequences. Then, with some additional adjustments of focus, one can discern a number of issues that cannot be shown in two-dimensional space. They are briefly discussed as follows. First and importantly, one can get a better idea of the complex threat situation and the ultimate threat - state failure. Second, an even deeper examination of the vision of contemporary wars reveals the shadows of things that have been and of those that will be on the road ahead. Third, a closer look at the familiar and troubling world map exposes some signposts on the road ahead that indicate the most significant changes in the landscape. Finally, our magical microscope reveals a short list of the basic challenges and tasks that can help discerning civilian and military leaders negotiate the road through the new global security environment.     

Optimal search for a moving target with the option to wait

We investigate the problem in which an agent has to find an object that moves between two locations according to a discrete Markov process (Pollock, Operat Res 18 (1970) 883–903). At every period, the agent has three options: searching left, searching right, and waiting. We assume that waiting is costless whereas searching is costly. Moreover, when the agent searches the location that contains the object, he finds it with probability 1 (i.e. there is no overlooking). Waiting can be useful because it could induce a more favorable probability distribution over the two locations next period. We find an essentially unique (nearly) optimal strategy, and prove that it is characterized by two thresholds (as conjectured by Weber, J Appl Probab 23 (1986) 708–717). We show, moreover, that it can never be optimal to search the location with the lower probability of containing the object. The latter result is far from obvious and is in clear contrast with the example in Ross (1983) for the model without waiting. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009     

Optimizing barge utilization in hinterland container transportation

In hinterland container transportation the use of barges is getting more and more important. We propose a real‐life operational planning problem model from an inland terminal operating company, in which the number of containers shipped per barge is maximized and the number of terminals visited per barge is minimized. This problem is solved with an integer linear program (ILP), yielding strong cost reductions, about 20%, compared to the method used currently in practice. Besides, we develop a heuristic that solves the ILP in two stages. First, it decides for each barge which terminals to visit and second it assigns containers to the barges. This heuristic produces almost always optimal solutions and otherwise near‐optimal solutions. Moreover, the heuristic runs much faster than the ILP, especially for large‐sized instances.     

On Brokers,Commodification of Information and Liberian Former Combatants

ABSTRACT

This article investigates research brokers and commodification of information. When combined with inherently asymmetric research relationships and successful gatekeeping, brokers create demand and become indispensable. Potential negative effects of brokerage and commodification of information are discussed through experiences studying former combatants in Liberia. There bargains with brokers who could facilitate access to this hidden population resulted in a vicious circle as brokers confirmed what researchers wanted to hear. The attention to this issue was first brought by subsequent ethnography and participant observation, which also offer the promise of an ethically defensible way of collecting information.